Heat actuated mechanism



- 8- 1931- I G. l. RYOCKWOOD 1,819,124

HEAT ACTUATED MECHANISM Filed May 5, 1930 Q60) 2 7.171 00% WOW Patented Aug. 18, 1931 1 1 PATENT OFFICE eno'nen '1. Roonwoop, or; WORCESTER," MASSACHUSETTS, nssrenon To Rooxwoon SPRINKLER, COMPANY or mAssAcH sETTs, or WORCESTER, MASSACHUSETTS, A

' oonronn IoN onMAssAcnUsETTs HEAT Ac'runTEn MECHANISM Applicatlonflled May 5, 1930. Serial No. 450,005;

'This invention relates to a heat-actuated mechanism for releasinga weight or initiatingother mechanical or electrical efiects.

It is the object of myinvention'to provide a mechanism in which the operationis determined by the rate of rise intemperature of the adjacent atmosphere, but isindependent of the actual temperature; Y I

A further feature of the invention relates to the provision of a mechanism in which a definite and predetermined resistance is provided to the operation of the mechanism, so that a definite minimum dilferential resultant of pressures in two essential parts of the device must be developed before release or actuationof the mechanismecontrolled thereby; My invention fjurther ;,relates to arrangements and combinations of partswhich will be. hereinafter described and more particu larly pointed out in the appended claims.

; A preferredform ofthe invention is shown in the drawing which isa diagrammatic view,

partlyin section, showing the construction and relation, of the several parts of my 1nvention. v

,Referringto the drawing, invention, in

the preferred form comprises a pair of pressure chambers-10 and 11 mounted onsupporting rods 12, on which they may be adjustably secured in spaced relation.;-;The chambers 10 and 11 are reversed in positionv relative "to each other and their adjacent faces are closed by fiexibledia'phragms 15,. A stud 16 is curedto the centers of the diaphragms 15 and serves to: clamp I discs 7 1 7; against the outer faces of the diaphragms-15. The center of the stud 16 is also pivotallyconnected at 18 to one end ofa release, lever 20which is pivoted at 21 on one of the supports 12. a I r The upperchamber 10v s connected by pipes .30 and'31to one end of a tubular coil '32, the oppositeend of whichis closed ati33. vA receptacle 40 in the formof a closed cylinder, oriof' someother compact shape, isv connected by; pipes 41 and42 to thelower; pressure cham berlllr The closed receptacle 40 is preferably 1 but not necessarily of such size andshape that itmaypbe mountedwithin the coilsofthe tubular ,member 32; The pipes 31 and 41 may be extended to connect with pressure chambers in additional pressure-controlled apparatus if so desired.

. The lever 20 when moved in an anti-clockwise direction, as indicated by the arrow (1, is designed to release a weight or to initiate some other mechanical or electrical effect. For the purposes of illustration, I have shown a trigger lever pivoted at 51 and engaging a lug or projection 52 on the lever 20. A weight W-may be hung on the lever 50 and when released the fall of the weight may be utilized to produce or initiate any desired effect. A sliding weight 53 is mounted on the lever 20, which may be raduated, as indicated at 54, to show the adjusted position of the weight.

Having described the construction of my improved heat-actuated mechanism, the operation thereof is as follows:

Under normal and even temperature conditions, the fluid pressures in the chambers 10 and 11 will be substantially equal and the parts will remain in the position shown in the drawing,-with the lug 52 engaging the trigger lever 50.

If there is a slow rise in temperature, the liquid or gaseous fluid in the coil 32 and in the receptacle 40 will expand at so nearly the same rate that the weight 53 on the lever 20 will hold the lever stationary. Even under a gradual rise in temperature, the pressure in the upper chamber 10 will increase slightly more rapidly than in the lower chamber 11,

due both to the greater surface of the outer coil 32 and to the more protected position of the inner receptacle 40. For both of these reasons, more time is required to heat a given volume of fluid in thereceptacle 40. Such a slight difierence in pressure, caused by a gradual rise, would not equal the predetermined difierential resultant necessary to raise the weight 53 and, release the lever '50. This minimum predetermined resultant may be selectively varied by adjustment of the weight 53. I 1 If, however, there is an abrupt rise in the temperature of the atmosphere surrounding the coil 32 andthe receptacle 40, the pressure in-v the coil 32 and chamber 10 will rise much morerapidly than the pressure in the'receptacle and chamber 11, due to the greater surface of the coil and the more exposed position thereof. This difference in pressure due to an abrupt rise in temperature of the atmosphere is sufficient to overcome the weight and release the lever 20.

It will be evident that the adjustment of the weight 53 away from the pivot 21 will necessitate an increase in the differential resultantacting on the lever 20 and will thus necessitate a more abrupt change in temperature before the device operates. On the other hand, an adjustment of the weight 53 to the left or toi'ard the pivot 21 will make the.

mechanism more sensitive and responsive to a less abrupt change in temperature.

lYhile I have shown the lever 20 acting to directly release the weighted lever, this is for purposes of illustration only and the lever 20 may be utilized to initiate any other mechanical or electrical eil'ect.

Obviously a single coil and receptacle 40 may be connected to a plurality of pressure chambers 10 and 11 and thus control a series of levers 20 spaced at desired distances from each other.

It is desirable that the receptacle 40 be placed inside of the coil 32 so that the two elements may be exposed to substantially the same temperature conditions, but satisfactory operation may often be secured when the receptacle 4O not surrounded by the coil 32, so long as the two elements are so closely adjacent as to be similarly effected by a rapid rise in temperature.

On a rapid drop in temperature, the pressure in the chamber 10 will be less than in the chamber 11 but this negative difference in pressure is inoperati e, as it merely crowds the lever 20 down against the endof the lever and no other etlect takes place. I

The relative capacities of the coil 32 and the receptacle -10 may be substantially varied but the capacity of the coil is commonly not greater than that of the receptacle.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is -l. A heat-actuated mechanism comprising opposed fluid-operated devices assembled and mounted to afford simultaneous exposure thereof to substantially identical atmospheric conditions, mechanism controlled by the differential resultant of a relatively abrupt change in the temperature of the atmosphere thereof, and means to predetermine the minimum eiiective differential resultant.

2. A heat-actuated mechanism comprising opposed fluid-operated devices assembled and mounted to afford simultaneous exposure thereof to substantially identical atmospheric conditions, mechanism controlled by the differential resultant of a relatively abrupt change to the temperature of the atmosphere thereof, and means to predetermine the minimum effective differential resultant, said latter means being adjustable to vary the predetermined minimum.

3. A heat-actuated mechanism comprising opposed fluid-operated devices, a separate fluid container connected in a closed system with each of said devices, said separate conta-iners being assembled and mounted to afford simultaneous exposure thereof to substantially identical atmospheric conditions and being differently responsive to an abrupt rise in temperature of the atmosphere surrounding both of said devices, mechanism controlled by the difierential resultant of said abrupt temperature rise on two devices, and means to predetermine the minimum effective differential resultant. v v

4. The combination in a heat-actuated mechanism as set forth in claim 3, in which the more responsive container is more advantageously exposed to the surrounding atmosphere. v

5. The combination in a heat-actuated mechanism as set forth in claim 3, in which the more responsive container has a substantially larger surface area exposed to the surrounding atmosphere. 1

6. The combination in a heat-actuated mechanism as set forth in claim 3, in which the more responsive container has a substantially larger surface area exposed to the surrounding atmosphere and is also more effectively exposed to the atmosphere.

' 7. The combination in a heat-actuated mechanism as set forth in claim 3, in which one container is in the form of a coiled tube and the-other container is in the form of a, compact receptacle i 8'; The ycombination in a heat-actuated mechanism as set forth in claim 3, in which one container is in the form of a coiled tube and the other container is in the form of a compact receptacle positioned within the coils of said tube. l r

9. The combination in a heat-actuated mechanism as setforth in claim 3,'in which each container is in direct contact with the atmosphere and under substantialy the same atmospheric conditions.

10'. A heat-actuated mechanism comprising two pressure chambers, separate diaphragms covering said chambers and both connected to a control member, mechanism controled by said member, and heat-responsive containers each connected to one of said pressure chambers and having different heatreceiving characteristics, said containers being assembled and mounted to afford simul taneous exposure thereof to substanti'aly identical atmospheric conditions and said control member being actuatedby the diflertial resultant of the fluid pressures on said diaphragms. 1

11. The combination in a. heat-actuated mechanism as set forth in claim 10, in which means is provided to hold said control memher from movement until a predetermined diflerential resultant is developed.

12. The combination in a heat-actuated mechanism as set forth in claim 10 in which said control member comprises a lever and in which a weight is movably mounted on said lever, by selective adjustment of which the predetermined minimum diflerential resultant may be varied.

In testimony whereof I have hereunto affixed my signature.

GEORGE I. ROGKWOOD. 

